There is an urgent need for interventions to increase hepatitis C virus (HCV) treatment uptake among HIV/HCV-co-infected persons. End-stage liver disease is now a leading cause of death among HIV-positive persons, largely due to untreated chronic HCV infection, and rates of HCV treatment uptake remain low despite significant advances in the effectiveness of HCV treatment. This study will develop an intervention addressing patient-level barriers (Information, Motivation, and Behavioral Skills) to HCV treatment uptake in HIV-co-infected patients and test its feasibility, acceptability, and preliminay efficacy. Based on formative research, we have developed the Psychosocial Readiness Evaluation and Preparation for hepatitis C treatment (PREP-C). PREP-C is a structured web-based interview that provides an assessment of a client's psychosocial readiness to begin HCV treatment and identifies domains of functioning which require intervention to improve treatment readiness. PREP-C has been piloted in almost 100 patients and a telemedicine resource for health care providers was launched in 2012 (www.prepC.org). In this study, we will develop and test an integrated assessment-behavioral intervention to increase HCV treatment initiation among HIV-co-infected patients. Our specific aims are: (1) To formally adapt existing behavioral medicine interventions based on PREP-C assessment to target individual barriers (Information, Motivation, and Behavior Skills) to HCV treatment initiation in HIV/HCV-co-infected patients who are medically eligible for HCV treatment, pilot test and refine the tailored intervention in 15 HIV/HCV-co-infected patients, and finalize the intervention manual. (2) To conduct a pilot randomized clinical trial with 60 HIV/HCV-co-infected patients who are medically eligible for HCV treatment, comparing the nurse-delivered PREP-C intervention (n=30) with attention control (n=30) in order to evaluate patient acceptance, patient satisfaction, enrollment and retention, as well as preliminary efficacy (initiation of HCV treatment within 6 months of randomization and persistence and adherence to the first 12 weeks of treatment in those who do initiate treatment). We hypothesize that the PREP-C intervention will increase Motivation, Information, and Self-Efficacy leading to higher rates of HCV treatment initiation, persistence and adherence in the PREP-C intervention arm. Findings from this vanguard study will inform the design parameters of a larger, more rigorous evaluation in an R01 application, if results are promising. The PREP-C web-based assessment and intervention package is designed to be scalable and can be disseminated through the live PrepC.org web site. The proposed study is innovative in that it seeks to develop the first web-based intervention for health care providers t use to increase HCV treatment initiation in HIV/HCV-co-infected persons. The study can have a major public health impact by providing needed structured resources for health care providers to increase rates of HCV treatment initiation in HIV/HCV-co- infected persons, thereby reducing mortality due to end-stage liver disease.